<template>
  <span :endTime="endTime" :callback="callback" :endText="endText">
    <slot>
      {{content}}
    </slot>
  </span>
</template>
<script>
  export default {
    data () {
      return {
      content: ''
      }
    },
    props: {
      endTime: {
        type: String,
        default: ''
      },
      endText: {
        type: String,
        default: '已结束'
      },
      callback: {
        type: Function,
        default: ''
      }
    },
    mounted () {
     this.countdowm(this.endTime)
    },
    methods: {
      countdowm (endTimetimestamp) {
      // 传进来的时间转化为时间戳
      var timestamp = Date.parse(new Date(endTimetimestamp))

      let self = this
      let timer = setInterval(function () {
        let nowTime = new Date()
        // let endTime = new Date(timestamp * 1000)
        // let t = endTime.getTime() - nowTime.getTime()
        let t = timestamp - nowTime.getTime()
        if (t > 0) {
          let day = Math.floor(t / 86400000)
          let hour = Math.floor((t / 3600000) % 24)
          let min = Math.floor((t / 60000) % 60)
          let sec = Math.floor((t / 1000) % 60)
          hour = hour < 10 ? '0' + hour : hour
          min = min < 10 ? '0' + min : min
          sec = sec < 10 ? '0' + sec : sec
          let format = ''
          if (day > 0) {
            format = `${day}天${hour}小时${min}分${sec}秒`
          }
          if (day <= 0 && hour > 0) {
            format = `${hour}小时${min}分${sec}秒`
          }
          if (day <= 0 && hour <= 0) {
            format = `${min}分${sec}秒`
          }
          self.content = format
          } else {
           clearInterval(timer)
           self.content = self.endText
           self._callback()
          }
         }, 1000)
        },
        _callback () {
        if (this.callback && this.callback instanceof Function) {
           this.callback(...this)
         }
      }
    }
  }
</script>
